Power distribution units are used in particular in motor vehicles to distribute high electrical currents and are constituents, for example, of so-called central electrical systems. In the electrical systems of motor vehicles, central electrical systems constitute the interfaces between electrical or electronic control devices and electrical lines or line strands. The central electrical system substantially fulfils a distributor function, supplying electrical consumer units of the motor vehicle, such as for example antilock braking systems (ABS), electrical stability programs (ESP), windscreen wipers, indicators and the like, with electrical current or electrical voltage via electrical lines or wiring harnesses and monitoring the serviceability of these consumer units. The electrical consumer units are actuated by means of switching devices, which are arranged in pluggable manner in the central electrical system together with fuses of the consumer unit electrical circuits. In addition, central electrical systems may comprise slots for switches, resistors, relays, solder contacts, pins, tabs and the like, together with connection possibilities for wiring harnesses provided with electrical coupling members.
DE 10 2004 006 575 A1 discloses a power distribution unit exclusively using punched grid technology for a motor vehicle. After being punched out of sheet metal, the punched grid comprises a plurality of conductor track portions connected by connecting webs, into which conductor track portions holes have been punched on production of the punched grid, wherein press-fit contacts may be inserted into these holes. After the punching process, the punched grid is partially encapsulated by plastics injection molding and then the connecting webs between the conductor track portions are separated, in order to produce electrically separate areas on the punched grid. Then, the press-fit contacts are press-fitted into the holes in the conductor track portions.
In view of the disadvantageous nature of electrical power distribution units produced exclusively by punched grid technology (large structure, heavy weight) especially in the automotive sector, electrical power distribution units using printed circuit board technology are preferred.
Power distribution units using printed circuit board technology and the punched grids therefor are exposed to severe thermal loading due to the comparatively long current transport paths on the printed circuit board and sometimes narrow current transport paths on the punched grid. The reason for this is the comparatively large openings within the punched grid. In addition, this makes the punched grid unstable and the punched grid may rapidly suffer damage as a result.
With regard to the prior art relating to punched grids and electrical power distribution units, see also the explanations relating to FIGS. 1-3 of the drawings.
It is, therefore, an object of the invention to provide an improved electrical power distribution unit with an improved punched grid, wherein it is intended for the electrical power distribution unit to display improved thermal behavior and for the punched grid to be less susceptible to damage. Furthermore, it is intended that the electrical power distribution unit or the electrical punched grid should be cheaper to produce.